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Echocardiography vs CT in Lung Cancer
overload may lead to respiratory failure is probably correct. However, for this hypothesis to find clinical applications, the critical care practitioner must be in a position to diagnose muscle overload with confidence, rule out confounding variables (ie, other causes for respiratory failure), and possess the means to accurately quantitate inspiratory load. It is our firm belief that with the current state of technology these expectations are unrealistic. Even with the resources of a research study, the measurement of V02 in critically ill patients is exceedingly tedious, carries a high chance for experimental error, and has no predictive value. It has not been our intent to discourage clinical research on the mechanisms of respiratory failure, but merely to caution against the indiscriminate use of monitoring technology in clinical practice. BolfD. Hubmayr, M.D., F.C.C.E; Lynn M. Loosbrock; Delmar J. Gillespie, M.D., and]oseph R. Rodarte, M.D., Mayo Clinic, Rochester, Minnesota
REFERENCES 1 Hubmayr RD, Loosbrock LM, Gillespie DJ, Rodarte JR. Oxygen uptake during weaning from mechanical ventilation. Chest 1988; 9:1148-55 2 Prechter GC, Nelson SB, Hubmayr RD. COl setpoint determined in normal subjects during mechanical ventilation. Am Rev Respir Dis 1988; 137:67
Echocardlography va CT In Lung Cancer 7b the Editor:
I would like to comment about the report, "Echoeardiography in Determining Nonresectability of Carcinoma of the Lung" by Howard et al (Chest 1988; 94:1306-07). The paper deals with a failure of cr in determining invasion of the heart by a bronchogenic carcinoma. Echocardiography is presented as an important and underutilized tool for staging bronchogenic carcinomas. I would like to take issue with the chest radiograph and particularly with the scan displayed in the article. The chest radiograph (Fig 1 in their article) likely shows a peripheral right upper lobe mass with hilar and lower paratracheal lymph node enlargement indicative of stage IlIa. The legend to this film reads: "Hilar mass with postobstructive pneumonia. No radiographic evidence of unreseetability" I cannot concur with this interpretation. The legend to Figure 2 reads: UNoevidence of vascular pericardial or cardiac invasion or hilar adenopathy is present." The CT scan shown is at the level of the aortic arch and does not include the pericardium, the cardiac silhouette or the right hilus. This picture could not demonstrate invasion of these structures even if it were present. What is more disturbing is the fact that the scan reproduced in the article definitely shows an enlarged right pretracheal, retrocaval lymph node which is highly suspicious for metastatic disease and would probably preclude resection of this bronchogenic carcinoma. In conclusion, I have to disagree with the authors of this paper: the chest radiograph and the cr scan in this case show evidence for stage III disease. Echocardiography cannot compete on a routine basis with cr in staging bronchogenic carcinoma.
cr
cr
Ibm Stark, M.D.,
Professor of Radiology; Director, Thoracic Radiology Section, Loma LAnda University, Loma Lmda, California
To the Editor: We feel that the questions Dr. Stark has raised regarding our report are good and we will try to answer them as best we can. The official reading of the radiograph on our case report was hilar mass with postobstructive pneumonia. It may very well be that Dr. Stark's interpretation that the x-ray film showed a peripheral upper lobe mass with hilar and lower paratracheallymph node involvement may be true. In either case, at the University of South Carolina radiographic evidence of unresectahility means that the disease is not confined to the side of the chest involved. Hilar adenopathy or lower paratracheal node enlargement does not mean that the patient is unresectable. On biopsy, some enlarged nodes in the hilum and mediastinum often show no evidence of tumor. For this reason, our protocols mandate mediastinoscopy (or Chamberlain procedure for left upper lobe lesions) to assess mediastinal nodes. For staging purposes and prognosis it should be pointed out that NI disease is not equivalent to metastatic disease. It has been shown that a stage III-A lesion can be resected with improved survival. We do not feel it would be in the patients' best interest to deny them a chance at a cure based upon a chest x-ray film showing hilar or paratracheal mass alone. Your comments on the cr scan are absolutely correct. Space limitations precluded us from showing the whole CT scan. We chose a cut that showed both the peripheral and the hilar nature of the lesion. At our institution, we use the cr scan to look for M-l disease to guide us to biopsy an area outside the chest. cr scan 6ndings of enlarged lymph nodes do not deem our patients as unresectable for the reasons sited above. Again, we would like to emphasize that stage III disease does not mean that the patient has an unresectable tumor. We do not advocate that echocardiography compete with cr scanning in preoperative staging, but we feel it can be used to help evaluate what appears to be local extension into the pericardium or great vessels. Obviously, since some of the atria can be included in the resection (if no tumor is left behind), the extent of invasion will need to be quantified in some way At this point in time we are looking at this question, but do not have an answer as yet as to how to fully utilize the echocardiogram. If the echocardiogram were to show invasion of most of the atrium or a ventricle, then that patient should not undergo an exploratory thoracotomy. Since the echocardiogram is not invasive and may allow us to make a judgment as to whether or not a thoracotomy will lead to a curative resection, we feel that it may have a role in the preoperative staging of the patient with a bronchogenic carcinoma.
Darryl S. Weiman, M.D., F.A.C.S., and
Martin L. Howard, M.D. Dorn Veterans Administration Hospital and University of SC School of Medicine Columbia, South Carolina
Reprint requests: Dr. miman, Two lUchland Medicallbrk, Suite 402, Columbia, SC 29203
Diagnosing sarcoidosis JO
tne tuutor:
The article, "Diffuse Interstitial Pneumonitis and Fibrosis in Sarcoidosis" by Aisner and Albin (Chest 1988; 94:193-95) is of considerable interest. The authors report a case of sarcoidosis in which extensive interstitial pneumonitis and fibrosis were demonstrated in areas without active granuloma formation. They stress that: 1) interstitial pneumonitis has rarely been reported in sarcoidosis, and in their case was diffuse; 2) interstitial pneumonitis and fibrosis were found in regions distinct from granuloma formation; and 3) the finding of interstitial pneumonitis on transbronchial biopsy does not exclude a diagnosis of sarcoidosis. We believe these CHEST I 96 I 2 I AUGUS'T, 1989
447
REFERENCES 1 Hubmayr RD, Loosbrock LM, Gillespie DJ, Rodarte JR. Oxygen uptake during weaning from mechanical ventilation. Chest 1988; 9:1148-55 2 Prechter GC, Nelson SB, Hubmayr RD. COl setpoint determined in normal subjects during mechanical ventilation. Am Rev Respir Dis 1988; 137:67
Echocardlography va CT In Lung Cancer 7b the Editor:
I would like to comment about the report, "Echoeardiography in Determining Nonresectability of Carcinoma of the Lung" by Howard et al (Chest 1988; 94:1306-07). The paper deals with a failure of cr in determining invasion of the heart by a bronchogenic carcinoma. Echocardiography is presented as an important and underutilized tool for staging bronchogenic carcinomas. I would like to take issue with the chest radiograph and particularly with the scan displayed in the article. The chest radiograph (Fig 1 in their article) likely shows a peripheral right upper lobe mass with hilar and lower paratracheal lymph node enlargement indicative of stage IlIa. The legend to this film reads: "Hilar mass with postobstructive pneumonia. No radiographic evidence of unreseetability" I cannot concur with this interpretation. The legend to Figure 2 reads: UNoevidence of vascular pericardial or cardiac invasion or hilar adenopathy is present." The CT scan shown is at the level of the aortic arch and does not include the pericardium, the cardiac silhouette or the right hilus. This picture could not demonstrate invasion of these structures even if it were present. What is more disturbing is the fact that the scan reproduced in the article definitely shows an enlarged right pretracheal, retrocaval lymph node which is highly suspicious for metastatic disease and would probably preclude resection of this bronchogenic carcinoma. In conclusion, I have to disagree with the authors of this paper: the chest radiograph and the cr scan in this case show evidence for stage III disease. Echocardiography cannot compete on a routine basis with cr in staging bronchogenic carcinoma.
cr
cr
Ibm Stark, M.D.,
Professor of Radiology; Director, Thoracic Radiology Section, Loma LAnda University, Loma Lmda, California
To the Editor: We feel that the questions Dr. Stark has raised regarding our report are good and we will try to answer them as best we can. The official reading of the radiograph on our case report was hilar mass with postobstructive pneumonia. It may very well be that Dr. Stark's interpretation that the x-ray film showed a peripheral upper lobe mass with hilar and lower paratracheallymph node involvement may be true. In either case, at the University of South Carolina radiographic evidence of unresectahility means that the disease is not confined to the side of the chest involved. Hilar adenopathy or lower paratracheal node enlargement does not mean that the patient is unresectable. On biopsy, some enlarged nodes in the hilum and mediastinum often show no evidence of tumor. For this reason, our protocols mandate mediastinoscopy (or Chamberlain procedure for left upper lobe lesions) to assess mediastinal nodes. For staging purposes and prognosis it should be pointed out that NI disease is not equivalent to metastatic disease. It has been shown that a stage III-A lesion can be resected with improved survival. We do not feel it would be in the patients' best interest to deny them a chance at a cure based upon a chest x-ray film showing hilar or paratracheal mass alone. Your comments on the cr scan are absolutely correct. Space limitations precluded us from showing the whole CT scan. We chose a cut that showed both the peripheral and the hilar nature of the lesion. At our institution, we use the cr scan to look for M-l disease to guide us to biopsy an area outside the chest. cr scan 6ndings of enlarged lymph nodes do not deem our patients as unresectable for the reasons sited above. Again, we would like to emphasize that stage III disease does not mean that the patient has an unresectable tumor. We do not advocate that echocardiography compete with cr scanning in preoperative staging, but we feel it can be used to help evaluate what appears to be local extension into the pericardium or great vessels. Obviously, since some of the atria can be included in the resection (if no tumor is left behind), the extent of invasion will need to be quantified in some way At this point in time we are looking at this question, but do not have an answer as yet as to how to fully utilize the echocardiogram. If the echocardiogram were to show invasion of most of the atrium or a ventricle, then that patient should not undergo an exploratory thoracotomy. Since the echocardiogram is not invasive and may allow us to make a judgment as to whether or not a thoracotomy will lead to a curative resection, we feel that it may have a role in the preoperative staging of the patient with a bronchogenic carcinoma.
Darryl S. Weiman, M.D., F.A.C.S., and
Martin L. Howard, M.D. Dorn Veterans Administration Hospital and University of SC School of Medicine Columbia, South Carolina
Reprint requests: Dr. miman, Two lUchland Medicallbrk, Suite 402, Columbia, SC 29203
Diagnosing sarcoidosis JO
tne tuutor:
The article, "Diffuse Interstitial Pneumonitis and Fibrosis in Sarcoidosis" by Aisner and Albin (Chest 1988; 94:193-95) is of considerable interest. The authors report a case of sarcoidosis in which extensive interstitial pneumonitis and fibrosis were demonstrated in areas without active granuloma formation. They stress that: 1) interstitial pneumonitis has rarely been reported in sarcoidosis, and in their case was diffuse; 2) interstitial pneumonitis and fibrosis were found in regions distinct from granuloma formation; and 3) the finding of interstitial pneumonitis on transbronchial biopsy does not exclude a diagnosis of sarcoidosis. We believe these CHEST I 96 I 2 I AUGUS'T, 1989
447